Stopper for packaging container

ABSTRACT

Provided is a stopper for a packaging container. The stopper includes bridges for checking whether a screw-coupling type stopper is opened or not and a hinge portion where an inner concave groove is formed, thereby displaying whether the stopper is opened or not, thereby enabling the stable connection of a stopper body and a fixing ring, thereby maintaining a set opening angle of the stopper body in case of opening, to thus prevent the stopper body from drooping and being shaken, and thereby elastically carrying out opening and closing operations, to thus remarkably improve the feeling of use.

TECHNICAL FIELD

The present invention relates to a stopper for a packaging container,and more particular to a stopper for a packaging container, includingbridges for checking whether a screw-coupling type stopper is opened ornot and a hinge portion where an inner concave groove is formed, therebydisplaying whether the stopper is opened or not, thereby maintaining aset opening angle of the stopper body in case of opening, to thusprevent the stopper body from drooping and being shaken, and therebyelastically carrying out opening and closing operations, to thusremarkably improve the feeling of use.

BACKGROUND ART

In general, a container that contains liquid materials of oil, paint andchemical products as well as beverages such as water and milk, includesa container body having a mouth, and a stopper that opens and closes themouth of the container body. The stopper is largely classified into ascrew-coupling type or a one-touch type according to an opening andclosing structure.

In the case of a screw-coupling type stopper 130 shown in FIGS. 1 and 2,a female screw portion is formed on an inner circumferential surface ofthe stopper 130 in correspondence to a container body 110 on which amale screw portion is formed on an outer circumferential surface of themouth of the container body 130. In the case that the stopper iscompletely separated from the container body, it may be polluted orlost. Accordingly, a fixing ring 133 for preventing the stopper frombeing separated from the container body 110 is provided at the lowerportion of a stopper body 131 so that the stopper is maintained toconnect with the container body at the time of opening a container 100.

In addition, the stopper body 131 and the fixing ring 133 are connectedby a plurality of bridges 135 that are radially formed. When the stopperis opened, the bridges 135 are cut to then enable a user to recognizewhether or not the container 100 is opened.

By the way, since the fixing ring 133 is combined with the containerbody 110 so as to idle in the above-described conventional technology,the opened stopper body 131 idles together with the fixing ring 133, andthe stopper body 130 is located downwards by dead weight at the time ofpouring the contents, and then caught by the mouth or chine of the user,to thereby provide the user with the feelings of discomfort and burdensand cause dirtiness due to the stopper polluted by the contents.

Meanwhile, in the case of a one-touch type stopper 130A shown in FIG. 3,a fixing ring 133 a that is fixed to a container body and a stopper body131 a that performs opening and closing operations are connected by ahinge portion 135 a.

The hinge portion 135 a is formed thinly in thickness and with a stepdifference, in comparison with the stopper body 131 a and the fixingring 133 a. A width of the hinge portion 135 a that connects between thestopper body 131 a and the fixing ring 133 a is formed in a fashion thatthe width becomes gradually large as it goes toward both sides of thehinge portion from the middle portion of the hinge portion incorrespondence to spaces between the stopper body 131 a and the fixingring 133 a at the time of opening the stopper of the container.Accordingly, the stopper body can be stably connected with the containerboy at the time of opening.

However, the screw-coupling type stopper having the bridges according tothe conventional art has a technical limit with respect to an undercuttreatment to thereby make it difficult to perform a stable connectionbetween the stopper and the container and realize the hinge portion thatdoes not cause the stopper body to be shaken at the time of opening.

DISCLOSURE Technical Problem

To solve the above problems or defects, it is an object of the presentinvention to provide a stopper for a packaging container, includingbridges for checking whether a screw-coupling type stopper is opened ornot and a hinge portion where an inner concave groove is formed, therebydisplaying whether the stopper is opened or not, thereby maintaining aset opening angle of the stopper body in case of opening, to thusprevent the stopper body from drooping and being shaken, and therebyelastically carrying out opening and closing operations, to thusremarkably improve the feeling of use.

Technical Solution

To accomplish the above and other objects of the present invention,according to an aspect of the present invention, there is provided astopper for a packaging container, the stopper comprising: a fixing ringfor preventing separation from a container body and preventing idling; astopper body for opening and closing the container body, where a screwportion is formed on an inner circumferential surface of the stopperbody; a hinge portion for connecting the fixing ring and the stopperbody; and a plurality of bridges formed between the stopper body and thefixing ring, which are cut if the stopper is opened, wherein a cuttingline for extending a connection length to the stopper body is formed inthe fixing ring around the lower portion of the hinge portion, andwherein a concave groove, which is formed to the inside of the stopperbody and the fixing ring by an inner slider of an injection moldingmachine, is formed in the hinge portion in such a way that the concavegroove is formed with a level difference between the stopper body andribs of the fixing ring.

Advantageous Effects

Therefore, a stopper for a packaging container according to the presentinvention includes bridges for checking whether a screw-coupling typestopper is opened or not and a hinge portion where an inner concavegroove is formed, thereby displaying whether the stopper is opened ornot, thereby enabling the stable connection of a stopper body and afixing ring, thereby maintaining a set opening angle of the stopper bodyin case of opening, to thus prevent the stopper body from drooping andbeing shaken, and thereby elastically carrying out opening and closingoperations, to thus remarkably improve the feeling of use.

DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a conventional screw-coupling typestopper that is closed on top of a container.

FIG. 2 is a perspective view showing a state of opening the stopper fromof the container of FIG. 1.

FIG. 3 is a perspective view showing an opened state of a one-touch typestopper.

FIG. 4 is a partially cross-sectional view of a stopper injectionmolding machine according to an embodiment of the present invention inorder to manufacture a stopper according to the present invention.

FIG. 5 is a cross-sectional view showing a varying state of FIG. 4.

FIG. 6 is an exploded perspective view showing a core unit of FIG. 4.

FIG. 7 is a perspective view of a stopper according to an embodiment ofthe present invention.

FIG. 8 is a bottom perspective view of FIG. 7.

FIG. 9 is a perspective view showing a state of use of FIG. 7.

FIG. 10 is a longitudinal cross-sectional view of FIG. 7.

FIG. 11 is a bottom view of FIG. 7.

FIG. 12 is a cross-sectional view showing an opened state of FIG. 10.

FIG. 13 is an extracted enlarged view of a hinge portion that is viewedfrom the inside of the stopper of FIG. 7.

FIG. 14 is a cross-sectional view cut along a line D-D of FIG. 13.

FIG. 15 is a perspective view of a stopper according to anotherembodiment of the present invention.

FIG. 16 is a perspective view showing an opened state of FIG. 15.

FIG. 17 is a perspective view of a stopper according to still anotherembodiment of the present invention.

FIG. 18 is a perspective view showing an opened state of FIG. 17.

FIG. 19 is a perspective view of a stopper according to yet anotherembodiment of the present invention.

FIG. 20 is a longitudinal cross-sectional view of FIG. 19.

FIG. 21 is a cross-sectional view of another example corresponding toFIG. 20.

FIG. 22 is a cross-sectional view of still another example correspondingto FIG. 20.

BEST MODE

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

As shown in FIGS. 7 to 14, a stopper 30 for a packaging containeraccording to an embodiment of the present invention, includes: a fixingring 33 for preventing separation from a container body 10 andpreventing idling; a stopper body 31 for opening and closing thecontainer body 10, where a screw portion 311 is formed on an innercircumferential surface of the stopper body 10; a hinge portion 35 forconnecting the fixing ring 33 and the stopper body 31; and a pluralityof bridges 39 formed between the stopper body 31 and the fixing ring 33,which are cut if the stopper 30 is opened. In addition, a cutting line37 for extending a connection length to the stopper body 31 is formed inthe fixing ring 33 around the lower portion of the hinge portion 35. Inaddition, a concave groove “a”, which is formed to the inside of thestopper body 31 and the fixing ring 33 by an inner slider of a stopperinjection molding machine 200, is formed in the hinge portion 35 in sucha way that the concave groove “a” is formed with a level differencebetween the stopper body 31 and ribs of the fixing ring 33.

Here, the stopper injection molding machine 200 is specially designed inorder to injection-mold stoppers for packaging containers according tothe present invention.

As shown in FIGS. 4 to 6, the stopper injection molding machine 200includes: an upper circular plate 230 having an upper molding portion231 that molds the upper portion of a stopper outer shape and a pair ofslider operating pins 233 and 234 that are formed aslope to both sidesof the upper molding portion 231; a pair of outer sliders 241 and 243that are horizontally slid in mutually opposition to each other by theslider operating pins 233 and 234 on a stripper 260 that is locatedbelow the upper circular plate 230 and molds the lower portion of thestopper outer shape; and a core unit 250 that molds a stopper innershape.

The core unit 250 includes: a core body 251 in which a pocket 2511 isconcavely formed at a portion corresponding to the stopper hinge portionfor undercut treatment of the stopper hinge portion; and an inner slider253 in which an undercut portion 2533 for molding the stopper hingeportion is installed so as to go in and out with respect to the pocket2511.

The undercut portion 2533 is protrudingly formed at one side of theupper portion of the inner slider 253. In the case of the inner slider253, an insert portion 2531 that is located in the inside of the pocket2511 and a support portion 2536 that is extended from the insert portion2531 to the outside of the pocket 2511 and horizontally slid on thelower circular plate 270 in which a wedge hole 2537 is formed on thesupport portion 2536, are integrally formed. In addition, an elasticmember 255 that pushes the inner slider toward the inside of the pocketis provided at the rear end of the inner slider 253.

In addition, a wedge 235 that is inserted into and released from thewedge hole 2537 of the inner slider 253 is provided in the uppercircular plate 230.

The inner slider 253 is configured in a manner that the undercut portion2533 of the insert portion 2531 protrudes outwards to thus mold aconcave groove “a” (see FIG. 9) of the stopper hinge portion 35 duringinjection-molding a stopper, and the undercut portion 2533 of the insertportion 2531 enters the inside of the pocket 2511 of the core body 251to thus avoid releasing of the stopper from being interfered duringreleasing the completely molded stopper.

In addition, the core body 251 is cut so as to be separated into anupper core frame 251 a and a lower core frame 251 b around a supportwing molding portion 2515 that molds support wings 34 (see FIG. 8). Theupper core frame 251 a and the lower core frame 251 b are connected by aconnection screw 2516 whose screw head is placed in an inner space 2514located below the lower core frame 251 b and penetrates the lower coreframe 251 b to then be screw-connected with the upper core frame 251 a.A coil spring 2517 is provided between the lower core frame 251 b andthe screw head of the connection screw 2516.

In addition, the outer sliders 241 and 243 are symmetrically formed tohalve and mold the lower portion of the stopper outer shape andhorizontally move on the stripper 260.

The stopper injection molding machine 200 having the above-describedconfiguration is set to make the upper circular plate 230 and a pair ofthe outer sliders 241 and 243 mold the stopper outer shape, while theinner slider 253 of the core unit 250 protrudes from the outercircumference of the core unit 250, so that the undercut portion 2533 ofthe insert portion 2531 located in the pocket 2511 formed in the coreunit 251 molds the concave grooves of the stopper.

The inner slider 253 maintains the position firmly against pressuregenerated at the time of injecting a resin molten solution, since thesupport portion 2536 is fixed by the wedge 235, the upper portion of thewedge 235 is fixed to the upper circular plate, and the lower portion ofthe wedge 235 is inserted into a groove 271 formed on the lower circularplate 270.

Here, the upper core frame 251 and the lower core frame 251 b separatedfrom the core body 251 maintain a mutually close relationship by theconnection screw 2516 and the elastic force of the coil spring 2517.

At the step of discharging the stopper after having passed through thestep of injecting and hardening the resin molten solution, the uppercircular plate 230 rises up to thus make the slider operating pins 233and 234 fixed to the upper circular plate and the wedge 235 rise up.

If the inclined slider operating pins 233 and 234 rise up, a pair of theouter sliders 241 and 243 widen laterally, and the wedge 235 secedesfrom the wedge groove 2537 of the inner slider support portion 2536.

Here, the inner slider 253 from which the wedge 235 has seceded ispushed out to the inside of the pocket 2511 of the core body 251 by theelastic member 255 that is formed at the rear end thereof, and theundercut portion 2533 of the insert portion 2531 comes into the insideof the pocket 2511, to thereby allow the molded stopper to be dischargedwithout causing any interference.

In addition, the core body 251 that are separated into the upper coreframe 251 a and the lower core frame 251 b is caught by the support wing34 that is formed on the stopper 30 at the time of a rise-up of thestripper 260 for discharging the stopper, and thus the upper core frame251 a is lifted up from the lower core frame 251 b instantaneouslytogether with the stopper 30 that is an injection molding product.Accordingly, the gap between the upper core frame 251 a and the lowercore frame 251 b becomes spaced and the support wing 34 of the stoppersecedes smoothly through the gap.

When the upper core frame 251 a is lifted up, the screw-coupledconnection screw 2516 rises up together with the upper core frame 251 a.The rise-up gap becomes about 5 mm or so.

Then, the connection screw 2516 that has risen up together with theupper core frame returns to the original position by the coil spring2517 that is provided between the screw head of the connection screw2516 and the lower core frame 251 b, and the upper core frame 251 abecomes again in contact with the lower core frame 251 b. In a separateway, the stripper 260 that proceeds to rise up persistently pushes upthe stopper 30 to then discharge the stopper.

Meanwhile, the screw portion 311 of the stopper may be transformed asthe stopper is compulsively discharged by the stripper. However, sincethe whole circumference of the inner circumferential surface of thestopper is under equal pressure, at a state where hardening proceeds andflexibility is given, the shape of the screw portion is molded.

In a reverse way after having discharged the stopper, the stripper 260returns to the original position, the upper circular plate 230 descendsand the slider operating pins 233 and 234 and the wedge 235 descend. Asthe slider operating pins 233 and 234 descend, the outer sliders 241 and243 horizontally move and return to the original position in oppositionto the descending slider operating pins 233 and 234. As the wedge 235descends, the inner slider 253 is fixed to the outer circumference ofthe core unit 250 so that the undercut portion 2533 protrudes, tothereby prepare for the next injection molding work.

As described above, the stopper injection molding machine 200 includesthe inner slider 253 for molding the concave groove of the stopper hingeportion so as to come in and out with respect to the core body 251.Accordingly, the screw-coupling type stopper 30 including bridges 39(see FIGS. 8 and 9) for checking whether the stopper is opened or notbetween the stopper body 31 and the fixing ring 33, and the concavegroove hinge portion 35 can be injection molded in an accurate andprecise form.

In addition, in the case of the core unit 250, the core body 251 isseparately formed into the upper core frame 251 a and the lower coreframe 251 b on the basis of the molding portion of the stopper supportwing, to thereby smoothen secession of the support wing, and to thusminimize deformation and inferiority and remarkably enhance quality ofthe stopper that is an injection molding product.

As shown in FIGS. 13 and 14, a concave groove “a” of the hinge portion35 that is molded by the inner slider of the stopper injection moldingmachine 200 is formed in a shape of “

” in which the concave groove “a” is surrounded by arc-shaped curvatureportions “c1” and “c2” where the respective peaks of the stopper body 31and the fixing ring 33 lie adjacent to an extension line of a boundaryline “b” between the stopper body 31 and the fixing ring 33, andstraight line portions “d” that link both ends of the two arc-shapedcurvature portions “c1” and “c2” and the straight line portions “d” arepreferably cut open.

The mutual gap and curvature shapes of the two arc-shaped curvatureportions “c1” and “c2” are designed to have a set opening anglemaintained in a tensile form at the time of opening.

The hinge portion 35 is formed outwards in a convex curved form as thewidth from the top to the bottom becomes large, and becomes graduallythin toward a convex peak “f” from end points “e” where the stopper body31 and the fixing ring 33 are connected with a step difference.Accordingly, it is desirable to form the convex peak “f” in the minimumthickness.

For a stopper opening operation, the shape of the concave groove “a” ofthe hinge portion 35 and the ribs and the stepped portion of the stopperbody 31 and the fixing ring 33 should be accurately formed. Unless theyare accurately formed, a moment that opens the stopper body 31 wide isnot generated.

As described above, the hinge portion 35 requires for a precisedimension management of the stepped portion, thickness, outer convexity,and a shape of “

” of the concave groove “a.” In the case that the concave groove “a” isnot angularly formed but roundly formed, an angle that opens the stopperbody wide is not made. Thus, it is difficult to perform the function ofthe hinge portion 35.

The concave groove “a” having the accurately formed stepped portionaccompanies an undercut portion at the time of injection molding, andcan be injection-molded through the stopper injection molding machine200 having the inner slider 253.

In addition, since the concave groove “a” of the hinge portion 35 isformed in a shape of “

” in which the concave groove “a” is surrounded by arc-shaped curvatureportions “c1” and “c2” where the respective peaks of the stopper body 31and the fixing ring 33 lie adjacent to an extension line of a boundaryline “b” between the stopper body 31 and the fixing ring 33, andstraight line portions “d” that link both ends of the two arc-shapedcurvature portions “c1” and “c2” and the straight line portions “d” arepreferably cut open, the set opening angle is stably maintained in atensile form at the time of opening, so that the stopper body 31 doesnot droop and thus is not shaken unstably.

A design of an opening angle of the stopper body may vary according touse of a packaging container. In particular, a packaging container fordrinking water is designed so that a stopper body does not contact thenose of a user during drinking the contents.

In addition, since the opening angle is stably maintained in a tensileform, the opening angle of the stopper body is maintained upright and isprevented from being folded or drooping, when the container is inclinedat the opened state in order to pour the liquid-phase contents, to thusenhance the feeling of use and stability.

In addition, if the stopper body 31 is angularly varied above a limitangle at which an elastic force is maximized for opening and closingoperations by forming thickness of the convex peak portion “f” the mostthinly, an identical magnitude of the elastic force works in a reversedirection.

Accordingly, the stopper body is spread or closed by the inertia at therest angular range although the user does not apply any force, tothereby further enhance the feeling of use.

In addition, the cutting line 37 becomes open at the time of opening thestopper. In this case, a connection length between the stopper body 31and the fixing ring 33 is lengthened, and the stopper body 31 is openedat a state where the stopper body 31 has been connected with the fixingring 33 (see FIGS. 10 and 12).

According to an embodiment of the present invention, it is preferablethat a plurality of support wings 34 are formed on the innercircumferential surface of the fixing ring 33 and sides 341 that aretangent to the container body are formed in a straight line so that thesupport wings 34 are tangent to the container body 10 at a single point(see FIGS. 8 and 11).

As described above, since the sides 341 of the support wings 34 that aretangent to the container body are formed in a straight line so that thesupport wings 34 are tangent to the container body 10 at a single point,a triangular support structure is formed between the container body 10and the support wings 34, to thereby maintain an elastic force thatallows the support wings 34 to be pushed toward the container body.

According to the embodiment of the present invention, it is preferablethat the inner diameter 33 d of the fixing ring 33 is formed with a stepdifference greater than the inner diameter 31 d of the stopper body 31(see FIG. 10).

As described above, since the inner diameter 33 d of the fixing ring 33is formed greater than the inner diameter 31 d of the stopper body 31,the stopper is softly rotated during opening and closing, and isprevented from idling by the support wings 34.

In addition, a reinforcement rib 331 is protrudingly formed in an areaof the fixing ring 33 where the hinge portion 35 is formed, and a bentportion 3312 corresponding to the outer circumference of the stopperbody 31 is concavely formed in the reinforcement rib 331 (see FIG. 7).

The reinforcement rib 331 that is formed in the fixing ring 33reinforces the area of the hinge portion 35 of the fixing ring 33, andis crookedly formed, to thus increase a withstanding force as well asprevent the stopper body 31 from being interfered during opening.

The shapes of the hinge portion 35 and the concave groove “a” accordingto the present invention are formed in various forms.

According to other embodiments of the present invention, as shown inFIGS. 15 to 22, a hinge portion 35 a, 35 b or 35 c includes a centerconnection portion and outer connection portions that are spaced fromeach other at both sides of the center connection portion and are inopposition to each other. Any one of the center connection portion andthe outer connection portions becomes a folding type connector orfolding connectors “X” and the other becomes pullers or a puller “Y”that maintains a set opening angle between the stopper body and thefixing ring during opening the stopper.

The folding type connector or folding connectors “X” are literallyformed in a folding form. Thus, part of the folding type connector orfolding connectors “X” is protruded outwards, and the concave groove “a”is deeply formed in the folding type connector or folding connectors“X.” In addition, the folding type connector or folding connectors “X”perform a connection function between the stopper body 31 and the fixingring 33 and also assist the puller or pullers “Y.”

In contrast, the puller or pullers “Y” play a role of pulling thestopper body 31 and the fixing ring 33 to thereby prevent a gap betweenthe stopper body 31 and the fixing ring 33 from becoming open above aset angle during opening.

As shown in FIGS. 15 and 16, according to another embodiment of thepresent invention, the hinge portion 35 a is configured so that thecenter connection portion 351 is formed into the folding connector “X”to thus horizontally form the concave groove “a” on the hinge portion 35a, and the outer connection portions 352 become more distant outwardsfrom the center connection portion 351 and are formed into the pullers“Y” that widen the width from the top to the bottom and are formed in aconvex curvature form.

The hinge portion 35 a maintains only a connection state between thestopper body 31 and the fixing ring 33 since the center connectionportion 351 becomes the folding connector “X,” and the outer connectionportions 352 at both sides of the center connection portion 351 becomethe pullers “Y” to thus apply pulling elastic forces that maintain theopening angle at both sides thereof during opening, and to therebymaintain the set opening angle so as to prevent the stopper body fromdrooping.

In addition, the outer connection portions 352 formed of the respectivepullers “Y” are formed gradually outwards in a convex curvature form andThe convex peak portion is formed in minimum thickness as the width fromthe top to the bottom becomes large. Accordingly, if the stopper body 31is angularly varied above a limit angle at which an elastic force ismaximized for opening and closing operations, the stopper body operatesat the rest angular range although the user does not apply any force, tothereby enhance the feeling of use.

As shown in FIGS. 17 and 18, according to still another embodiment ofthe present invention, the hinge portion 35 b is configured so that thecenter connection portion 353 is formed into the puller “Y” and theouter connection portions 354 are formed into the folding connectors“X.”

The outer connection portions 354 protrude outwards more and more asthey become more distant from the center connection portion 353.

The center connection portion 353 of the hinge portion 35 b becomes thepuller “Y” to thus generate a pulling elastic force and the outerconnection portions 354 become the folding connectors “X” to thus assistthe puller “Y.”

As shown in FIGS. 19 to 22, according to yet another embodiment of thepresent invention, it is preferable that the center connection portion355 of the hinge portion 35 c is formed into the puller “Y” in which theconcave grove “a” is formed in a ‘∠’ shape or ‘(’ shape in itscross-section, and the outer connection portions 356 are formed into thefolding connectors “X.”

The hinge portion 35 c has a characteristic that the center connectionportion 355 becomes the puller “Y” and is protrudingly formed outwardsin a bent or curved form, in which a bent portion or a curved portionhas been opened wide and returns to the original angle at the time of anopening operation, to then generate a pulling force by an elastic forcethat maintains a return state.

In the case of the center connection portion 355 that is the puller thatis formed in a bent form, the bent portion is located at the lowerportion of the center connection portion 355 as shown in FIGS. 19 and20, or the bent portion is located at the upper portion of the centerconnection portion 355 as shown in FIG. 21, in which the bent edgeportion may be rounded.

As described above, a stopper for a packaging container according to thepresent invention includes bridges for checking whether a screw-couplingtype stopper is opened or not and a hinge portion where an inner concavegroove is formed, thereby displaying whether the stopper is opened ornot, thereby enabling the stable connection of a stopper body and afixing ring, thereby maintaining a set opening angle of the stopper bodyin case of opening, to thus prevent the stopper body from drooping andbeing shaken, and thereby elastically carrying out opening and closingoperations, to thus remarkably improve the feeling of use.

In addition, the stopper 30 for a packaging container is formed into ascrew-coupling type stopper having the hinge portion that is providedwith each of various types of concave grooves “a” and the bridgesdisplaying whether or not the stopper is opened differently from aone-touch type stopper, and thus can be manufactured by the stopperinjection molding machine having the inner slider that comes in and outwith respect to the core unit.

As described above, the present invention has been described withrespect to particularly preferred embodiments. However, the presentinvention is not limited to the above embodiments, and it is possiblefor one who has an ordinary skill in the art to make variousmodifications and variations, without departing off the spirit of thepresent invention. Thus, the protective scope of the present inventionis not defined within the detailed description thereof but is defined bythe claims to be described later and the technical spirit of the presentinvention.

INDUSTRIAL APPLICABILITY

As described above, a stopper for a packaging unit according to thepresent invention is a screw-coupling type stopper that includes bridgesdisplaying whether or not the stopper is opened and a hinge portion onwhich an inner concave groove is formed, thereby providing advantages ofdisplaying whether the stopper is opened or not, of enabling the stableconnection of a stopper body and a fixing ring, of maintaining a setopening angle of the stopper body in case of opening, to thus preventthe stopper body from drooping and being shaken, and of elasticallycarrying out opening and closing operations.

1. A stopper for a packaging container, the stopper comprising: a fixingring for preventing separation from a container body and preventingidling; a stopper body for opening and closing the container body, wherea screw portion is formed on an inner circumferential surface of thestopper body; a hinge portion for connecting the fixing ring and thestopper body; and a plurality of bridges formed between the stopper bodyand the fixing ring, which are cut if the stopper is opened, wherein acutting line for extending a connection length to the stopper body isformed in the fixing ring around the lower portion of the hinge portion,and wherein a concave groove, which is formed to the inside of thestopper body and the fixing ring by an inner slider of an injectionmolding machine, is formed in the hinge portion in such a way that theconcave groove is formed with a level difference between the stopperbody and ribs of the fixing ring.
 2. The stopper for a packagingcontainer according to claim 1, wherein a concave groove of the hingeportion is formed in a shape of “

” in which the concave groove is surrounded by arc-shaped curvatureportions where the respective peaks of the stopper body and the fixingring lie adjacent to an extension line of a boundary line between thestopper body and the fixing ring, and straight line portions that linkboth ends of the two arc-shaped curvature portions and the straight lineportions are cut open.
 3. The stopper for a packaging containeraccording to claim 1, wherein the hinge portion is formed outwards in aconvex curved form as the width from the top to the bottom becomeslarge, and becomes gradually thin toward a convex peak from end pointswhere the stopper body and the fixing ring are connected with a stepdifference, to thus form the convex peak in the minimum thickness. 4.The stopper for a packaging container according to claim 1, wherein aplurality of support wings are formed on the inner circumferentialsurface of the fixing ring and sides that are tangent to the containerbody are formed in a straight line so that the support wings are tangentto the container body at a single point
 5. The stopper for a packagingcontainer according to claim 1, wherein the inner diameter of the fixingring is formed greater than the inner diameter of the stopper body. 6.The stopper for a packaging container according to claim 1, wherein areinforcement rib is protrudingly formed in an area of the fixing ringwhere the hinge portion is formed, and a bent portion corresponding tothe outer circumference of the stopper body is concavely formed in thereinforcement rib.
 7. The stopper for a packaging container according toclaim 1, wherein a hinge portion comprises a center connection portionand outer connection portions that are spaced from each other at bothsides of the center connection portion and are in opposition to eachother, and wherein any one of the center connection portion and theouter connection portions becomes a folding type connector or foldingconnectors and the other becomes pullers or a puller that maintains aset opening angle between the stopper body and the fixing ring duringopening the stopper.
 8. The stopper for a packaging container accordingto claim 1, wherein the center connection portion is formed into thefolding connector to thus horizontally form the concave groove on thehinge portion, and the outer connection portions become more distantoutwards from the center connection portion and are formed into thepullers that widen the width from the top to the bottom and are formedin a convex curvature form.
 9. The stopper for a packaging containeraccording to claim 8, wherein the center connection portion of the hingeportion is formed into the puller, and the outer connection portionsthereof are formed into the folding connectors.
 10. The stopper for apackaging container according to claim 8, wherein the center connectionportion of the hinge portion is formed into the puller that is formed ina ‘∠’ shape or ‘(’ shape in its cross-section, and the outer connectionportions thereof are formed into the folding connectors.